The goal of this K23 Career Development Award is for Dr. Beckwith to acquire the skills necessary to become an independent clinical investigator specializing in the delivery of HIV testing services to substance users, particularly in the incarcerated setting. Career goals include training in: 1) the methodologies of clinical research with special attention to infectious diseases epidemiology;2) health services research;3) conducting research among substance users;and 4) ethics of conducting research in the incarcerated setting. The research plan proposes to: 1) analyze the existing Project START database to assess barriers and facilitators to HIV testing and counseling in the jail setting;2) conduct qualitative interviews with in-prison providers and jail detainees to assess barriers and facilitators to rapid HIV testing in jail;and 3) perform a prospective randomized controlled trial in the Rhode Island Department of Corrections jail comparing a rapid HIV testing and counseling intervention with standard HIV testing and counseling. The intervention will consist of individualized HIV risk reduction counseling based on the Project RESPECT brief counseling intervention coupled with rapid HIV testing. Jail detainees will be randomized to receive either the rapid HIV testing and counseling intervention (intervention arm) or standard HIV testing and counseling only (control arm). It is hypothesized that subjects in the intervention arm: 1) will receive their HIV test results more often;2) will engage in lower rates of HIV risk behavior following release from jail;and 3) for subjects newly diagnosed with HIV infection, will be more efficiently linked to HIV care in the community following jail release. To evaluate these outcomes, all subjects will complete a baseline HIV risk behavior assessment in jail. Subjects will be randomized to their respective study arm and there will be follow-up visits scheduled six weeks and 24 weeks following jail release in order to evaluate receipt of HIV test results, changes in HIV risk behavior following release from jail, and establishment of HIV care in the community. Dr. Beckwith will be mentored by Dr. Timothy P. Flanigan from Brown Medical School in Providence, Rl. Through this award, Dr. Beckwith aims to advance the delivery of HIV testing and prevention services to persons incarcerated in jail.